Download 16.4 Threats To Biodiversity

16.4 Threats To Biodiversity
KEY CONCEPT
The impact of a growing human population threatens
biodiversity.
16.4 Threats To Biodiversity
Preserving biodiversity is important to the future of the
biosphere.
o The loss of biodiversity has long-term effects.
• loss of medical and technological advances
• extinction of species
• loss of ecosystem stability
16.4 Threats To Biodiversity
Loss of habitat eliminates species.
• Habitat fragmentation prevents an organism from
accessing its entire home range.
– occurs when a barrier forms within the habitat
– often caused by human development
• Habitat corridors are a solution to the problem.
16.4 Threats To Biodiversity
Introduced species can disrupt stable relationships in an
ecosystem.
• An introduced species is one that is brought to an
ecosystem by humans.
– accidental
– purposeful
• Invasive species
can have an
environmental
and economic
impact.
16.4 Threats To Biodiversity
 Invasive species often push out native species.
• Burmese python (Florida Everglades)
• Introduced to the Florida Everglades from Asia (pet)
• It is a constrictor and as the population grows, park
officials worry that the endangered species here will fall
prey to the snake.
16.4 Threats To Biodiversity
 Invasive species often push out native species.
• mice (Australia)
• Introduced to Australia from Europe (stowaways on cargo
ships)
• Cost farmers millions of dollars in lost crops.
• Lack of predators to keep the population stable.
16.4 Threats To Biodiversity
 Invasive species often push out native species.
• kudzu (southeastern United States)
• Introduced from southeast Asia (ornamental house plant)
• Spread too quickly. “Chokes” out native species. Now
classified as a problematic weed species.
16.4
To Biodiversity
16.5Threats
Conservation
So, what can we do???
• Conservation methods can help protect and
restore ecosystems.
16.4
To Biodiversity
16.5Threats
Conservation
Sustainable development manages resources for present
and future generations.
• Sustainable development meets needs without hurting
future generations.
– resources meet current needs
– resources will still be available for future use
• The timber industry has started to adopt sustainable practices.
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To Biodiversity
16.5Threats
Conservation
 Global fisheries have adopted several sustainable
practices.
• rotation of catches
o Gives time to recover
• fishing gear review
o Avoids damaging sea floor
• harvest reduction
o Slows harvest, allowing recovery
• fishing bans
o Replenishes populations
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Conservation
Conservation practices focus on a few species but benefit
entire ecosystems.
• The Endangered Species Act
works to protect individual
species from extinction.
• A listed species is often called
an umbrella species.
– the habitat in which the
species lives must be
protected
– other species are protected
because they share the
ecosystem
16.4
To Biodiversity
16.5Threats
Conservation
Protecting Earth’s resources helps protect our future.
• The Environmental Protection Agency (EPA) was created
in 1970.
– develops policies and regulations to protect the
environment.
• Legislation helps to protect the environment and
endangered species. The following are three important
laws:
• Clean Air Act
• Clean Water Act
• Endangered Species Act (this law recovered the bald eagle)
16.4
To Biodiversity
16.5Threats
Conservation
• There are several ways that people can help protect the
environment.
– control population growth
– develop sustainable technology
– change practices
– protect and maintain ecosystems